STUDY OF THE DEGREE OF WATER AND SOIL POLLUTION OF THE UMBELUZI RIVER AND ITS TRIBUTARIES AS A RESULT OF AGRICULTURAL ACTIVITIES AND AGGREGATE EXTRACTION Article Kuleshova Yu.V. ESPI–2023 ENVIRONMENTAL STUDIES AND PROTECTION ISSUES — 2023 Proceedings of the International Youth Scientific and Academic Conference. Moscow, April 21, 2023: In Two Parts: PART 1. РУДН. 2023. P. 100-103